1. Field of the Invention
This invention relates to radial arm saws, and more particularly to a stop mechanism for controlling the length of workpiece infeed for each cut of the saw to facilitate the rapid and accurate production of a large number of equally sized pieces.
2. Description of the Prior Art
In many manufacturing processes it is necessary to cut an elongated workpiece such as a board into a large number of equally sized pieces. Such cutting can advantageously be accomplished with a radial saw slidably mounted on a horizontal arm which is suspended above a horizontally disposed planar table. The principal problem involved in using such saws for the above-described purpose is the time required to ensure that the pieces are accurately cut. Certainly, the operator of the radial arm saw can measure each piece individually either with a scale or reference piece, but this procedure requires the operator to make a measurement and mark a board in accordance with the measurement before each cut. This requires the operator to remove his hand from the saw and possibly change his position to perform the measurement and marking. Also, the need for the operator to place his hands on the workpiece near the track of the saw to measure and mark the workpiece exposes the operator's hands to possible injury from the rotating sawblade.
The workpiece may be cut into a large number of equally sized pieces by utilizing a mechanical stop to control the distance which the workpiece is fed into the saw for each cut. One such device is disclosed in U.S. Pat. No. 2,892,474 issued to Hiebert. In the Hiebert device a stop is normally positioned above the workpiece, but is actuated downwardly into the path of the workpiece by a relay. However, it is necessary for the cut piece to be moved clear of the stop before the stop is once again lowered to limit the feed of the workpiece into the saw. Significantly, the advancing end of the uncut workpiece could not be used to move the cut piece clear of the stop since the cut piece would prevent the stop from projecting downwardly to a position where it could abut the end of the workpiece to terminate infeed. Additionally, the range of workpiece thickness which the stop mechanism can accommodate is limited.